This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction The Human Immunodeficiency Virus (HIV)-infection profile changed dramatically after the introduction of highly active antiretroviral therapy. AIDS-related opportunistic conditions decreased, while Hepatitis C Virus (HCV)-infection became a primary factor for disease prognosis. Puerto Rico has one of the highest prevalence of HIV/AIDS in the US, and HCV co-infection has emerged as a major public health problem on the island, particularly among injecting drug users (IDUs), who have an estimated co-infection rate greater than 50%. HCV co-infection has an increasing effect on the natural history of HIV/AIDS disease, which underlines the importance of creating and evaluating educational and interventional strategies that can be directed at reducing this co-infection. A multimedia educational intervention, based on the Health Beliefs Model and Social Cognitive Theory was developed and implemented to reduce HCV-associated risk behaviors among injecting drug users (IDUs). Our study is an educational and counseling intervention directed at increasing both HCV-related knowledge and the perception of the severity of and (an individual's) susceptibility to the infection. The education and prevention intervention modules consist of four computer-based sessions that are intended to increase: 1) HCV knowledge, 2) the perception of HCV susceptibility and disease severity, 3) the perception of the efficacy of HCV protective measures, and 4) risk reduction self-efficacy perception. In this second study phase, the intervention was implemented and evaluated in a population of people living with HIV/AIDS (PLWHA). The following relates the study's progress and achievements over the last six years. Study Aims: First General Aim. The selection of a cohort of Puerto Rican PLWHA whose members reported using injecting drugs, and who were characterized according to their HCV knowledge and risk behaviors. Study participant recruitment. A total of 281 participants were recruited for the study. HCV prevalence screening with an HCV qualitative test was done on the participants at their entry into the study and again one year later. In addition, HCV viral load and HCV genotype testing were done in all serologically positive blood samples. By June 2009, 133 cases and 92 controls received one or more intervention session. The intervention group received the education and counseling interventions 8 weeks after having entered the study;the control group received the education and counseling interventions 6 months following their entry into the study. The sessions were held at weeks zero, two, four, and eight in the intervention group. A total of 255 participants received the first intervention, 218 the second, 210 the third, and 198 the fourth. A stipend was given to all study participants to cover travel and dietary expenses. HCV educational information, personal hygiene kits, bottled water, and snacks were given to each participant during the interventional process. No adverse reactions were reported during the recruitment, intervention, or follow-up, nor was there evidence of such reactions during the blood draws. Three participants were withdrawn from the study by the investigator, because they did not fulfill the inclusion criteria;two refused to participate after signing the consent form. There were no events in which breach of confidentiality occurred. Significance of the study HIV/AIDS is one of the most relevant public health problems in Puerto Rico. AIDS prevalence is among the highest in the United Stated and its territories. Over fifty percent of the PLWHA in Puerto Rico are IDUs, with risk behaviors that significantly increase the probability of HCV co-infection. Additionally, the medical management of HCV in PLWHA is complicated by the high costs, immune suppression, and the potential drug interactions and toxicities. The increasing evidence that emphasizes the synergistic role of HIV-HCV co-infection in the morbidity and mortality of PLWHA has focused our attention on the evaluation of HIV secondary prevention strategies targeted at reducing HCV co-infection and its attendant complications. Thus, this study evaluated the prevalence of risk behaviors that could increase HCV co- and super-infection in a cohort of mostly medically indigent Puerto Rican PLWHA. The study also implemented and evaluated an educational and counseling intervention, directed at decreasing risks of HCV co- and super-infection in IDU PLWHAs. This study adds important data that will lead to the successful management of a difficult medical scenario directed to be organized as one element within the context of HIV secondary prevention strategies.